Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 1,399	$ 1,374	$ 5,661	$ 5,313	$ 5,051
Expenses:
Operating-related expenses			1,769	1,700	1,651
Selling and general expenses			1,443	1,550	3,144
Depreciation			85	90	86
Amortization of intangibles			96	67	48
Total expenses			3,393	3,407	4,929
(Gain) loss on dispositions			(1,101)	(11)	9
Operating profit	857	424	3,369	1,917	113
Interest expense, net			181	102	59
Income from continuing operations before taxes on income			3,188	1,815	54
Provision for taxes on income			960	547	245
Income (loss) from continuing operations			2,228	1,268	(191)
Discontinued operations, net of tax:
Income from discontinued operations			0	0	18
Gain on sale of discontinued operations			0	0	160
Discontinued operations, net			0	0	178
Net income (loss)	569	276	2,228	1,268	(13)
Less: net income from continuing operations attributable to noncontrolling interests			(122)	(112)	(102)
Net income (loss) attributable to S&P Global Inc.	537	248	2,106	1,156	(115)
Amounts attributable to S&P Global Inc. common shareholders:
Income (loss) from continuing operations			2,106	1,156	(293)
Income from discontinued operations			0	0	178
Net income (loss) attributable to S&P Global Inc.	$ 537	$ 248	$ 2,106	$ 1,156	$ (115)
Income (loss) from continuing operations:
Basic (in dollars per share)			$ 8.02	$ 4.26	$ (1.08)
Diluted (in dollars per share)			7.94	4.21	(1.08)
Income from discontinued operations:
Basic (in dollars per share)			0.00	0.00	0.66
Diluted (in dollars per share)			0.00	0.00	0.66
Net income (loss):
Basic (in dollars per share)	$ 2.07	$ 0.92	8.02	4.26	(0.42)
Diluted (in dollars per share)	$ 2.05	$ 0.91	$ 7.94	$ 4.21	$ (0.42)
Weighted-average number of common shares outstanding:
Basic (in shares)			262.8	271.6	271.5
Diluted (in shares)			265.2	274.6	271.5
Actual shares outstanding at year end (in shares)	258.3	265.2	258.3	265.2	272.0
Dividend declared per common share (in dollars per share)			$ 1.44	$ 1.32	$ 1.20